diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 1592e49a10b..da5a313f4b1 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -717,9 +717,13 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
                                       "LC_DYLD_INFO_ONLY")))
         return;
     } else if (Load.C.cmd == MachO::LC_UUID) {
-      // Multiple UUID load commands
+      if (Load.C.cmdsize != sizeof(MachO::uuid_command)) {
+        Err = malformedError("LC_UUID command " + Twine(I) + " has incorrect "
+                             "cmdsize");
+        return;
+      }
       if (UuidLoadCmd) {
-        Err = malformedError("Multiple UUID load commands");
+        Err = malformedError("more than one LC_UUID command");
         return;
       }
       UuidLoadCmd = Load.Ptr;
diff --git a/test/Object/Inputs/macho-invalid-uuid-bad-size b/test/Object/Inputs/macho-invalid-uuid-bad-size
new file mode 100644
index 00000000000..6e7351e76b3
Binary files /dev/null and b/test/Object/Inputs/macho-invalid-uuid-bad-size differ
diff --git a/test/Object/Inputs/macho-invalid-uuid-more-than-one b/test/Object/Inputs/macho-invalid-uuid-more-than-one
new file mode 100644
index 00000000000..5427811a9a4
Binary files /dev/null and b/test/Object/Inputs/macho-invalid-uuid-more-than-one differ
diff --git a/test/Object/macho-invalid.test b/test/Object/macho-invalid.test
index b8a1e10148f..64899d76126 100644
--- a/test/Object/macho-invalid.test
+++ b/test/Object/macho-invalid.test
@@ -283,3 +283,9 @@ INVALID-DYLIB-WRONG-FILETYPE: macho-invalid-dylib-wrong-filetype': truncated or
 
 RUN: not llvm-objdump -macho -private-headers %p/Inputs/macho-invalid-dylib-no-id  2>&1 | FileCheck -check-prefix INVALID-DYLIB-NO-ID %s
 INVALID-DYLIB-NO-ID: macho-invalid-dylib-no-id': truncated or malformed object (no LC_ID_DYLIB load command in dynamic library filetype)
+
+RUN: not llvm-objdump -macho -private-headers %p/Inputs/macho-invalid-uuid-more-than-one  2>&1 | FileCheck -check-prefix INVALID-UUID-MORE-THAN-ONE %s
+INVALID-UUID-MORE-THAN-ONE: macho-invalid-uuid-more-than-one': truncated or malformed object (more than one LC_UUID command)
+
+RUN: not llvm-objdump -macho -private-headers %p/Inputs/macho-invalid-uuid-bad-size  2>&1 | FileCheck -check-prefix INVALID-UUID-BAD-SIZE %s
+INVALID-UUID-BAD-SIZE: macho-invalid-uuid-bad-size': truncated or malformed object (LC_UUID command 0 has incorrect cmdsize)